<html>
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
	<title>Document</title>
</head>
<body>
	<p>点击下面的按钮，将代码块循环五次：</p>
	<button onclick="myFunction()">点击这里</button>
	<p id="demo"></p>
	<script type="text/javascript">
		function myFunction(){
			var x="";
			for(i=0;i<5;i++){
				x=x + "The number is" + i + "<br>";
			}
			document.getElementById('demo').innerHTML=x;
		}
		cars=["BMW","Volvo","Saab","Ford"];
		var i=2,len=cars.length;
		for (;i<len;) {
			document.write(cars[i] + "<br>");
			i++
		}
	</script>
</body>
</html>